A couple of aspiring reality-TV stars from Northern Virginia appear to have crashed the White House's state dinner Tuesday night, penetrating layers of security with no invitation to mingle with the likes of Vice President Biden and White House Chief of Staff Rahm Emanuel.

Tareq and Michaele Salahi -- polo-playing socialites known for a bitter family feud over a Fauquier County winery and their possible roles in the forthcoming "The Real Housewives of Washington" -- were seen arriving at the White House and later posted on Facebook photos of themselves with VIPs at the elite gathering.

"Honored to be at the White House for the state dinner in honor of India with President Obama and our First Lady!" one of them wrote on their joint Facebook page at 9:08 p.m.

A woman describing herself as a publicist for the Salahis denied that they were interlopers. Pressed for details, Mahogany Jones sent a statement saying simply: "The Salahis were honored to be a part of such a prestigious event. . . . They both had a wonderful time."

While the White House offered no official explanation, it appears to be the first time in modern history that anyone has crashed a White House state dinner. The uninvited guests were in the same room as President Obama, first lady Michelle Obama and Indian Prime Minister Manmohan Singh, although it is unknown whether they met the Obamas and the guest of honor.

"Everyone who enters the White House grounds goes through magnetometers and several other levels of screenings," said Ed Donovan, a spokesman for the Secret Service. "That was the case with the state dinner last night. No one was under any risk or threat."

Donovan said a preliminary internal investigation Wednesday identified "a Secret Service checkpoint which did not follow proper procedure to ensure these two individuals were on the invited guest list." He declined to give further details. An administration official said the White House will conduct its own review.

The Salahis, both in their 40s, showed up about halfway through the guest arrivals. A Marine announced their names, and the couple -- he in a tux, she in a striking red and gold lehenga (traditional Indian formalwear) -- swept pass reporters and photographers, stopping several times to pose for pictures. They then walked into the White House lower hallway, where they mingled with guests on the red carpet before heading up to the cocktail reception in the East Room.

Later, they posted pictures that seem to chart their course through the night: Michaele posing with Marines outside near the White House doors, and with Katie Couric and Rep. Ed Royce (R-Calif.) inside the mansion. In the East Room, the Salahis both cozied up to D.C. Mayor Adrian Fenty and his wife, Michelle.

But the best was yet to come: Once inside the dinner tent, they got pictures that appeared to show them with ABC's Robin Roberts, Bollywood composer AR Rahman, PepsiCo CEO Indra Nooyi, Obama Chief of Staff Emanuel (identified as "Ron" in the couple's Facebook photo caption) and two with a grinning vice president. The photos end there -- no shots of the Salahis sitting at a table, their seatmates or the post-dinner entertainment.

How could it happen? A former White House senior staffer -- who more than a decade ago encountered a crasher at one of the executive mansion's less-fancy parties -- offered this theory:

A savvy pair of crashers, dressed to the nines, might arrive on foot at the visitors' entrance, announce their names -- then express shock and concern when the security detail at the gate failed to find them on the guest list. On a rainy night like Tuesday, with a crowd of 300-plus arriving, security might have lost track of or granted a modicum of sympathy to a pair who certainly looked as though they belonged there. If their IDs didn't send up any red flags in the screening process, they would be sent through the magnetometers and into the White House.

And yet, the former staffer noted: Someone from the White House social office should have been posted at the guest entrance with the guards.

Once visitors were in, no one necessarily would ask them for further identification. They could check their coats, give their names to the Marine on duty, walk past reporters and into the lower hallway where guests picked up their table assignments. They would pass the junior staffers handing out seating cards and walk on up the stairs for cocktails in the East Room.

Later, all guests were directed to head for the dinner tent on the South Lawn. Facebook photos suggest that the Salahis walked into the tent; it's unclear when they left. Reporters were cleared from the entryway by the time dinner seating got under way. There is no security checkpoint to leave the grounds.

The Salahis, longtime fixtures in local horse-country society, have recently seemed destined for national fame via reality TV. Michaele, a striking model-thin blonde who used to be a Redskins cheerleader, has been widely reported to be in contention as one of the "Real Housewives" in the forthcoming D.C. edition of the hit Bravo cable series. Although Bravo has not officially finalized its cast, its cameras have followed the couple at numerous parties -- including the "America's Polo Cup" held on the Mall in September, part of a series of tournaments the Salahis founded a few years ago.

Abby Greensfelder, head of the local production team Half Yard Productions, referred questions about the Salahis to Bravo. A Bravo representative declined to comment.

Even before their brush with reality TV fame, the couple had gained some notoriety for a long-running feud with Tareq's parents, Dirgham and Corinne Salahi, over control of the family's Oasis Winery in Hume, Va.

Last year, Tareq accused his mother's attorney of punching him; the lawyer was found not guilty. Court records show that Oasis filed for bankruptcy in February, with Tareq listed as "debtor designee."

A note on the winery's Web site Wednesday promised a reopening for business in 2010.

The America's Polo Cup has also endured controversy, last year drawing a lawsuit from a Middleburg caterer over alleged non-payment. That suit remains unresolved.

Hours before the White House denied that the Salahis were legitimate guests, The Post asked the couple via Facebook how they happened to attend the dinner. Tareq responded: "India is the challenger in the America's Polo Cup World Championships June 11/12 2010, and they are very excited in this first ever cultural connection being hosted on the DC National Mall since Polo is one of the primary sports in India."

When pressed about why they did not appear on the official list, he added, "it was last-minute attending."